Department of Biochemistry, Memorial University of Newfoundland, St John's, Newfoundland.

Abstract

BACKGROUND AND OBJECTIVES:

High dietary fat intake has been reported to cause an alteration in lipid metabolism that is associated with an increased risk of cardiovascular disease. In the present study, an animal model was used to evaluate the effects of feeding diets rich in different fatty acids to mothers during pregnancy and lactation, and the effects of the maternal diet on parameters of lipid metabolism in adult offspring. The interaction between the offspring's own diet and the programming due to the maternal diet was also evaluated.

METHODS:

Female C57BL/6 mice were fed a high-fat diet (20% fat [weight to weight]) rich in either saturated fatty acids (SFA) or polyunsaturated fatty acids (PUFA) for two weeks before mating, during pregnancy and until weaning. The offspring were divided into two groups; each group was fed a high-fat diet enriched in either SFA or PUFA for eight weeks after weaning. The groups were designated as SFA/SFA (diet of the mother/diet of the offspring), SFA/PUFA, PUFA/PUFA and PUFA/SFA. Blood and tissues were collected at the end of the eight-week feeding period after an overnight fast.

RESULTS:

The plasma total cholesterol and low density lipoprotein cholesterol concentrations were significantly higher in the SFA/SFA group than in all other groups, whereas the PUFA/PUFA group had the lowest total cholesterol and low density lipoprotein cholesterol concentrations. Plasma high density lipoprotein cholesterol concentrations were significantly higher in the PUFA/SFA group than in the PUFA/PUFA and SFA/PUFA groups, whereas plasma triglyceride concentrations were not different among the groups.

CONCLUSIONS:

The data suggest that high maternal dietary fat intake during pregnancy affects lipid metabolism in the adult offspring. However, it appears that the offspring's own diet is also important in maintaining the regulation of lipid metabolism.

Experimental design for the study. Eight-week-old female C57BL/6 mice were fed high-fat diets rich in either SFA or PUFA for two weeks, and they continued on the special diets during mating, pregnancy and lactation. Offspring obtained from each group of mothers were divided into two groups: one-half were fed the same diet as that of the mother, whereas the other half were fed the other diet. The four dietary groups of the offspring were SFA/SFA (diet of the mother/diet of the offspring), SFA/PUFA, PUFA/PUFA and PUFA/SFA. Offspring were continued on the special diets for eight weeks after weaning. At the end of the feeding period, blood and tissues were collected after an overnight fast. w/w Weight to weight

A maternal diet high in saturated fatty acids (SFA) has deleterious effects on the plasma lipids of the offspring. Plasma total cholesterol (A), low density lipoprotein (LDL) cholesterol (B), high density lipoprotein (HDL) cholesterol (C) and triglycerides (D) were assayed as described in the Methods section. Differences between the groups were evaluated using one-way ANOVA with the Student-Newman-Keuls post hoc test, where different superscripts (ie, ‘a’, ‘b’ and ‘ab’) represent significant differences. The individual effects of the maternal diets (MD) and the offspring’s diets (OD) were assessed by two-way ANOVA. All of the values are expressed as means ± SEM (n=8), and values were considered significant if P≤0.05. The four dietary groups are SFA/SFA (diet of the mother/diet of the offspring) (open bar), SFA/polyunsaturated fatty acids (PUFA) (hatched bar), PUFA/PUFA (solid bar) and PUFA/SFA (grey bar)

Hepatic lipid profile of the offspring fed various diets. Hepatic triglycerides (A), total cholesterol (B), free cholesterol (C) and cholesterol esters (D) were assayed as described in the Methods section. Differences between the groups were evaluated by one-way ANOVA with the Student-Newman-Keuls post hoc test, where different superscripts (ie, ‘a’, ‘b’ and ‘ab’) represent significant differences. The individual effects of the maternal diets (MD) and the offspring’s diets (OD) were assessed by two-way ANOVA. The four dietary groups are saturated fatty acids (SFA)/SFA (diet of the mother/diet of the offspring) (open bar), SFA/polyunsaturated fatty acids (PUFA) (hatched bar), PUFA/PUFA (solid bar) and PUFA/SFA (grey bar)